This is a revised application. Side airbags are increasingly used in the automotive world. Torso side airbags are designed to protect the chest of the occupant and are often available with head-curtain side airbags. Field data are primarily anecdotal regarding the efficacy of side airbags, principally because they are still nascent. A primary focus of the proposed project is to evaluate the efficacy of torso side airbags with respect to the older occupant. Recent data from government consumer crash tests reveals that torso side airbags do not always improve the safety performance of a vehicle. Also, data from our local trauma center indicates that occupants over 59 may have 3 or 4 times the number of rib fractures than a young person in a similar side impact crash. The working hypothesis of the project is that torso side airbags mitigate chest trauma and do not increase the injury spectrum to the rib cage of older occupants. The hypothesis is based on the biomechanical knowledge that, when properly positioned, airbags absorb energy, which would have otherwise been imparted to the occupant in a lateral impact, thus minimizing trauma. We also hypothesize that when an out-of-position scenario is added to the fragility of the older driver, the risk of injury and harm from the impact might have a combination effect. For torso side airbags, such scenarios need to be clearly defined before an evaluation of its efficacy can be made. It is our hypothesis that, just as children are the vulnerable group that may receive disbenefit from frontal airbags, the older driver may be the vulnerable group that receives disbenefit from side airbags. The characteristic features of the research design include the use of a full-scale sled to conduct whole-body side impact simulations at velocities representative of field data; the use of torso side airbags representative of the modern vehicle fleet; various transducers to obtain chest deformations; and a detailed autopsy to carefully identify and document injuries, including number of rib fractures. This multifaceted design will duplicate side impacts in a controlled laboratory environment for in-position and out-of-position occupants for young and old age groups.